onthefbi's investigation.>> reporter: sources say cia director david petraeus was never the target of an fbi investigation. but when his name surfaced in another probe, agents became concerned that petraeus or his e-mail accounts may have been compromised. it all began a few months ago when a female acquaintance of the cia director received a series of harassing e-mails. which apparently referenced petraeus. the woman who sources say is not a government official notified the fbi. federal agents quickly traced those e-mails back to petraeus' biographer paula broadwellment it then revealed evidence of the extramarital affair including numerous cryptic e- mails between the retired four star general and broadwell. she spent time with petraeus in afghanistan doing research for her book "all in -- the education of general david petraeus." last february on a tour, the married mother of two children made this comment -- >> i'm not in love with david petraeus but i think he does represent a terrific role model for people, men and women no matter what. >> reporter: petraeus also a married fa